Battle of Sentinum

Intro
When the Romans learned the Samnites and the Etruscans were planning to combine their forces and tried and persuaded the Gaul and Umbrians to join them, the Roman senate appointed L. Volumnius Flamma as proconsul ordered the 2 propraetors CN. Fulvius and P. Megellus to take positions outside Rome with 2 armies.

Consul Fabius Maximus left a legion under command of propraetor L. Scipio near Clusium and returned to Rome. The legion was slaughtered by the Gaul.

Now the 2 consuls moved their armies towards the combined enemy army. Fabius ordered the 2 propraetors Fulvius and Megelus to move their armies into Etruscan territory and destroy there all they could and plunder it.

This had the desired effect: The Etruscans left the battlefield to protect their homes.

Battle
Once the Etruscans were out of the way Fabius and Decius offered battle to the Gauls and Samnites. For two days nothing much happened. On the third day the armies met.

The Romans had adopted the organization of their army from the Samnites and placed their manipels (Livius often makes the mistake to write about cohorts, an organization introduced by G. Marius) with space between them. The Gaul simply attacked as one mass.

Vital information
Where Fabius initially restrained his troops to stay where the were, Decius tried to force a victory too soon. Decius may have been young at that time but he certainly not inexperienced; he was consul for the third time! He simply missed a vital piece of information.

Chariots
He assumed command of his cavalry and attacked the Gallic horse. He pushed them back, so they had the fighting foot soldiers on their right. But the Gaul had another a card on their sleeve. They now attacked Decius' cavalry with chariots. Possibly the Etruscans had left these behind, since this technology belonged to to their arsenal. Either way the Romans did panic and started to flee. When Decius couldn't stop them he decided to devote himself to the death as his father had done before him.

Self sacrifice
Together with the pontifex M. Livius, who he had kept near his side he fulfilled the rituals and then he dashed into the Gaul who killed him with many spears.

Many historians doubt if both self sacrifices have really happened. The story of the father is indeed a little too beautiful; two consuls with the same dream and pontifices to confirm the consequences. But if he did self sacrifice himself it would be logical for his son to follow his example. Especially at a moment when everything seemed to be lost.

New Úlan
His deed made the Romans who saw this happen eager to retrieve Decius' body. Somehow the fighting spirit returned, Fabius sent a part of his auxiliaries, who he had kept in reserve to the left wing that was now commanded by the pontifex Livius, who Decius had appointed propraetor.

On the right wing the Samnites started to show signs of fatigue. Fabius thought it was time to take the initiative.

Fabius takes the initiative

Livius writes Fabius sent 500 Campanian horse to attack the Gaul in the back at the moment he heard of Decius' death, more likely he sent them as soon as he saw he wasn't gonna need them himself.

This because he sent the Roman cavalry from his wing to attack the Samnites on their flank. If all his cavalry had gone from the flank they had to protect, the Samnite cavalry would certainly have attacked that unprotected flank.

He now moved all his reserves into the battle.

This was more than the Samnites could resist and they started to flee to their camp.

Victory
Fabius' army went into pursuit while the Samnites tried to reach the relative safety of their camp. But most of them couldn't get in because of the crowd they were and had to fight.

Fabius also sent the principes of his third legion to attack the Gaul in the rear, together with the 500 Campanian horse. Thus also the Gaul were slaughtered.